Free radical injury to membranes begins with abstraction of a hydrogen atom from polyunsaturated fatty acids in phospholipids. The self-propagating chain reaction that follows is called:

• A Lipofuscinogenesis
• B Lipid peroxidation ✓
• C Saponification
• D Protein cross-linking by malondialdehyde

Explanation

Lipid peroxidation is the autocatalytic chain reaction in which a radical abstracts hydrogen from a polyunsaturated fatty acid side chain, forming a lipid radical that reacts with oxygen to yield a peroxyl radical, which attacks adjacent fatty acids and propagates the cycle. This destroys membrane phospholipids and increases permeability. Lipofuscin is a wear-and-tear pigment, not a chain reaction. Protein cross-linking by aldehydes such as malondialdehyde is a downstream consequence, not the membrane chain reaction itself.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.